The American Cancer Society guidelines for breast screening with magnetic resonance imaging: an argument for genetic testing.

BACKGROUND The American Cancer Society (ACS) guidelines for screening with breast magnetic resonance imaging (MRI) recommend MRI for women who have a lifetime risk > or = 20% of developing breast cancer. Genetic testing for breast cancer gene (BRCA) mutations is offered to women who have a risk > or = 10% of carrying a mutation. The objectives of the current study were 1) to identify the number of women in a breast cancer screening population who had > or = 20% lifetime breast cancer risk and, thus, were candidates for screening MRI; and 2) to determine the number of women who had > or = 10% risk of BRCA mutation yet had <20% lifetime risk of breast cancer and, thus, may not have been identified as candidates for MRI screening. METHODS From 2003 to 2005, women who underwent screening mammography completed a self-administered questionnaire regarding breast cancer risk factors. For each patient, the lifetime breast cancer risk and the risk of BRCA mutation was determined by using the computerized BRCAPRO breast cancer risk-assessment model. RESULTS Of 18,190 women, 78 (0.43%) had > or = 20% lifetime risk of breast cancer, all of whom had > or = 10% risk of carrying a BRCA mutation. An additional 374 women (2.06%) had <20% lifetime breast cancer risk but > or = 10% risk of mutation. Overall, there were 183 (1%) predicted mutation carriers, 27 women (0.15%) who had > or = 20% lifetime risk of breast cancer, and 62 women (0.34%) who had > or = 10% risk of mutation but <20% lifetime breast cancer risk. CONCLUSIONS The ACS guidelines for breast MRI screening may systematically exclude MRI screening for many women who have a substantial risk for BRCA mutation. The current results demonstrated a need for greater awareness of breast cancer risk factors in the screening mammography population, so that high-risk women can be identified and given access to genetic testing and counseling regarding all risk-reducing interventions.